Steam-superheater.



G. P. DRAVO.

STEAM SUPERHEATER.

APPLICATION FILED SEPT- 27' 915- 1 1 85, 1 85 Patented May 30, 1916.

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G. P. DRAVOQ STEAM SUPERHEATER. I APPLlCATI ON FILED SEPT-27 1915.

1 ,1 85, 185. 1 Patented May 30, 1916.

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GEORGE P. DRAVO, F MILWAUKEE, Wisconsin.

STEAM-SUPERHEATER.

Specification of Letterslatent.

Patented May 30, 1916.

Application filed September 27, 1915. Serial No. 52,780.

To all whom it may concwn Be it known that I, GEORGE P. DRAVO, a. citizen of the United States, residing at Milwaukee, in the county of Milwaukee and State of Visconsin, have invented certain new and useful Improvements in Steam- Superheaters, of which the following is a specification, reference being had to the ac-. companying drawing, forming a part thereof.

The main objects of this invention are to agitate the steam as it passes through the superheater in such a manner as to make its heating surface more efiective, facilitate superheating the steam and increase the efficiency of the superheater, and generally to improve the construction and operation of apparatus of this class. i

It consists in the construction, arrangewent and combination of parts as hereinafter particularly described and pointed out in the claims.

In the accompanying drawing like characters designate the same parts in the several figures.

Figure 1 is a side elevation of a superheater embodying the invention as applied to a boiler and boiler furnace of a wellknown type; Fig. 2 is an end elevation of 'the same as viewed from the rightrelative to Fig. l, the boiler setting or furnace being omitted; Fig. 3 is a greatly enlarged section on the line 3-3, Fig. 1, of an outlet header forming a part of the apparatus; and Fig.

(4 is a similar section on theline 4-4, Fig. 2,

of a coupling header connecting the heating tubes of a single unit.

The device is applicable to various types of boilers and boiler furnaces or heaters 40 ,separate from the boilers.

In Figs. 1 and 2 an ordinary return flue boiler 1, is diagrammatically shown, and in Fig. 1 a part of the boiler, setting or furnace is shown in section, 2 designating the bridge wall of the furnace, and 3 a heating chamber at the rear end of the. boiler. The superheater in its simplest or elemental form, consists of a heating tube 4, which extends into or is exposed inthe heating [chamber of the boiler furnace or of an independent heater, and is connected with the boiler, and a smaller tube 5, extending axially and opening into the heating tube and having a connection with the boiler or other source of fluid pressure for supplying it with fluid at a higher pressure than that of the steam in the heating tube into which the I smallerv tube discharges. For a boiler and boiler furnace of the type shown, the super heater preferably comprises a number of these units arranged and connected substantially as shown in Figs. 1 and 2. The heating tubes 4 are connected at one end, the upper end as shown in the present case, with openings in the lower slde of inlet headers 6, and at their lower ends with openings in the upper side of coupling headers 7, arranged at right angles or transversely to the he'aders 6; Like or similar heating tubes 8, forming extensions of the tubes 4 and arranged parallel therewith, are connected at their lower ends with openings in the upper sides of the coupling headers 7 and at their upper ends with openings in the lower sides of outlet headers 9, which, are like or similar in construction to the inlet headers 6. The

inlet headers 6 are connected by a pipe 10 with the boiler. The smaller tubes 5 are connected by a pipe 11 .and branches 12, with the boiler or some other source from which steam or other fluid may besupplied to said tubes at a higher pressure than that of the steam in the heating tubes. The pipe 10 is provided with an ordinary cut-oft valve 13, and the pipe 11 is provided with a similar valve 14. When the heating tubes 4 and 8 and the smaller tubes 5 are connected with the same boiler, in order to supply the inner tubes with steam at a higher pressure than that in the heatingtubes, the pipe 10 is provided with an automatic regulating valve 15,of anywell known or suitable construction for reducing the pressure of the steam supplied to the heating tubes and maintaining a substantially constant difference, say three orfour pounds,betwfeen the pressure in the heating tubes and the pressure in the boiler and smaller tubes supplied, directly therefrom through the pipe 11 and branches' lQ. The regulating valve 15 is made adjustableby means of a sectional weight. 16 for varying the difference between the pressures in the outer or heating tubes and in the smaller or agitator tubes 5. The extensionheating tubes 8 may also be provided, like the tubes 4, with agitator tubes 15,,as shown. The superheated steam is taken or delivered from the outlet headers 9 through an outlet pipe 17 connected with said headers, as shownin Fig. 1.

The inlet, outlet and coupling headers 6,

7 and 9, maybe constructedfor convenience in assembling the parts of the superheater, as shown in detail in .Figs. 3. and 4. The inlet and outlet headers 6 and 9 are formed opposite and in alinement with the openings for the tubes and 8, with corresponding openings through which an expanding tool is inserted to expand and secure the ends of the tubes in the headers, and which are provided with threaded plugs or closures 18, as shown. The inner tubes 5 are threaded or otherwise fastened at one end in these plugs or closures, and extend therefrom axially into the outer heating tubes 4 and 8,

their other ends being closed, as shown in Fig. 4. The branch pipes 12 are also connected with the plugs or closures 18, in alinement with the tubes 5. The coupling headers 7 are formed as shown in Fig. 4, with openings for the purpose of expanding the lower ends of the tubes 4 and 8, and these openings are provided with closures 19, seated inside of the headers and fastened in place by yokes 20 and bolts 21. The tubes 5 are formed, as shown in Figs. 1 and 3, with lateral openings 22, directed into the annular steam passage or space between said tubes, and preferably spirally arranged to produce a whirling movement of the steam.

In the operation of the apparatus as shown. and described, the pressure of the steam in its passage from the boiler to the superheater through the pipe 10 is reduced by the regulating valve 15, and in its passage through the tubes 4 and 8 exposed in the heating chamber 3, the steam is superheatcd the superheated steam. being taken off through the outlet pipe 17 connected with the headers 9. Steam at substantially boiler pressure, supplied through the pipe 11 and branches 12 to the tubes 5, is discharged therefrom through the lateral openings 22 into the annular passages or spaces formed between them and the heating tubes 4 and 8, and mixes with and agitates the steam flowing at a lower pressure through said passages or spaces, thereby directing the steam against the larger tubes, rendering their heating surface more effective and facilitating the superheating of the steam in its passage therethrough.

Various changes in the construction and arrangement of parts of the superheater for adapting the same to boilers and furnaces or heaters of diflerent kinds under varying conditions, may be made without departure from the principle and scope of the invention as defined in the following claims.

I claim:

1. In a steam superheater the combination with a boiler and heating chamber of a heating tube exposed in said chamber and connected with the'boiler, a smaller tube forming with the heating tube an annular passage and opening into said passage, and

a connection for supplying the smaller tube with fluid at a higher pressure than that of the steam in the heating tube.

2. In a steam superheater the combination with a boiler and heating chamber, of a heating tube exposed in said chamber and connected with the boiler, a smaller tube extending axially and opening into the heating tube and connected with the boiler, and means in the connection between the heating tube and boiler for maintaining a lower pressure in said tube than in the smaller tube.

3. In a steam superheater the combination with a boiler and a heating chamber, of a heating tube exposed in said chamber and connected with the boiler, a smaller tube extending axially into the heating tube and having spirally arranged openings into the annular space between it and the heating tube, and a connection for supplying the smaller tube with fluid at a higher pressure than that of the steam in the heating tube.

4. In a steam superheater the combination with a boiler and a heating chamber, of a heating tube exposed in said chamber and connected with the boiler, a smaller tube extending axially and opening into the heating tube and connected with the boiler, and means for maintaining a lower pressure in the heating tube than in the smaller tube.

5. In a steam superheater the combination witha boiler and a heating chamber, of a heating tube exposed in said chamber and connected with the boiler, a smaller tube extending axially and opening into the heating tube and also connected with the boiler, and an automatic regulating valve in the connection between the heating tube and boiler adapted to maintain a lower pressure in the heating tube than in the smaller tube. i

6. In a steam superheater the combination with a boiler and a heating chamber, of a heating tube exposed in said chamber and connected with the boiler, a smaller tube ex tending axially and opening into the heating tube and also connected with the boiler, and an automatic regulating valve provided with means of adjustment in the connection be tween the heating tube and boiler for maintaining a lower pressure in the heating tube than in. the smaller tube and varying the difference'between the pressures in said tubes.

7. In a steam superheater the combination with a boiler and a heating chamber, of headers having alined openings in opposite sides thereof, one of the headers being connected with the boiler, a heating tube secured at the ends in the headers, removable closures for the openings opposite the ends of said tube, a tube of smaller diameter attached to the closure in one of the headers and extending axially and opening into the heating tube, and a connection with the smaller tube for supplying it with fluid at a higher pressure than that of the steam in the heating tube.

8. In a steam superheater the combination with a boiler and heating chamber, of an inlet header connected with the boiler and having alined openings in opposite sides thereof, a heating tube exposed in said chamber and secured at one end in one of said openings, a closure fitted to the opposite opening, a tube of smaller diameter secured at one end to said closure and extending axially and opening into the heating tube, and a connection through said closure with the smaller tube for maintaining a higher pressure therein than in the heating tube.

9. In a steam superheater the combination with a boiler and a heating chamber, of an inlet header connected with the boiler and having alined openings in opposite sides thereof, an outlet header having an outlet connection and alined openings in opposite sides thereof, heating tubes connected at one end with openings 1n said headers, a coupling header connecting said tubes at the other end and having openings in the opposite side in alinement with said tubes, re-

movable closures for the openings in the headers opposite said pipes, a tube of smaller diameter attached at one end to one of said closures and extending axially and opening into the opposite heating tube, and a connection with the smaller tube for supplying it with fluid at a higher pressure than that of the steam in the heating tubes.

10. In a steam superheater the combination with a boiler and heating chamber, of an inlet header connected with the boiler, an outlet header having an outlet connection, heating tubes exposed in said chamber and connecting said headers, smaller tubes extending from the inlet header axially into the opposite heating tubes and opening into the annular space between them and the inner tubes, and a connection for supplying the smaller tubes with fluid at a higher pressure than that of the steam in the heating tubes.

In witness whereof I hereto aflix my signature in presence of two Witnesses.

GEORGE P. DRAVO.

\Vitnesses:

CHAS. L. Gross, ALICE E. Goss.

copies of this patent may be obtained for fivecents each, by addressing the Commissioner of Patents. Washington. D. 0. 

